Patent Application No. 201110291009.9, titled self-energizing disc brake, discloses a brake which solves a problem that the disc brake has no self-energizing effect, especially the big problem to control the self-energizing disc brake. It also solves the problem of the small self-energizing range of the self-energizing ratio (generally, it is only 1-4) of the brake. The self-energizing ratio (Efficiency Factor) can be increased by one times—dozens of times or even more. This greatly expands the use range of the disc brake. However, such self-energizing disc brake needs inclined surfaces to be arranged at two sides of the brake disc, thereby causing the disadvantages of bigger size, complicated structure and too many sealing parts.
The disc brake on the car greatly improves the safety of the car. However, the disc brake has small braking force (low efficiency factor) and no self-energizing effect. It requires power assistance (a vacuum booster for a gasoline car) to brake the car, and is difficult to arrange a parking brake and an emergency brake. It is high cost, and the braking force will be very small after the engine is off, especially after the car has an accident flameout. Since the disc brake uses the hydraulic drive, it has a security risk of being lag which may fail to meet the security requirement. Accordingly, in order to ensure that the car has a big enough braking force at any time, the idle speed of the engine shall be adjusted to be a relatively high level, as the vacuum booster needs bigger vacuum to produce an assistant force. In this case, the car needs more fuel when the driver waits for traffic lights and during traffic jams, which is not good for the economy and the environment. In addition, when the brake is used in a diesel car, a double energy car and an electrical car, it needs to be provided additionally with a vacuum pump, which would significantly increase the costs. The common disc brake in the prior art also cost much when being provided as a parking brake.
In order that the disc brake can have self-energizing effect, people have carried out a lot of exploration. “Brake Technology Handbook” (Germany, B. Breuilh K. Bill, Machinery Industry Press, published in June, 2011, ISBN 978-7-111-34916-7, Page 359-Page 363) disclosed two electrically controlled disc brakes which are under experiment and promising, in which a method of single inclined-surface servo (wedge servo) is adopted. The braking is carried out by a motor via a transmission mechanism under the control of CPU (a computer). So far the disclosed electrically controlled disc brake cannot be exactly controlled. Another method used therein needs a high powered and big-sized motor which consumes lots of electricity that the power source can hardly supply. Additionally, the big size of the motor makes itself hard to be mounted by the wheel. Furthermore, the high cost of the high-powered and big-sized motor affects its implementation.
The invention provides a series of solutions related to a high self-energizing servo disc brake aiming at solving the following problems: as the common disc brake has a low efficiency factor, a power booster may be necessary; it is difficult to control the disc brake as the control force (power) is large; it may cost a lot to provide a parking brake with the disc brake; and other economic, security and environment problems caused by the high idle speed of the engine. This disclosure also solves the problem that it is difficult to control the self-energizing effect of the disc brake in the prior art. Furthermore, this disclosure can also compensate for the deformation of a machine body (a clamp body) of the brake produced when the braking is carried out, so as to reduce the operation stroke and increase the energizing ratio of the brake. When the braking force of a single-side double-inclined-surface disc brake is the same as that of the disc brake in the prior art, and their operation strokes are also the same, the operation force (the control force and the control power) of the brake of the invention can be several times or even dozens of times less than that of the brake in the prior art. Furthermore, the force therebetween is in linear relation. Therefore, the brake of the present invention can be very conveniently controlled. For example, an electrical servo mechanism (e.g. the motor) or the like may be used to carry out electrical control to realize EMB. However, the motor of the disc brake which carries out electrical control (EMB) in the prior art has very high power, big size and huge electric energy consumption, thereby affecting its use and promotion. The disc brake of this disclosure can directly carry out electrical control, and ABS, ASR, ESP, EBV, ECD and HDC can be directly controlled by CPU (computer). Therefore, the invention does not need a lot of hydraulic and mechanical mechanisms any more, reducing manufacture cost, improving reliability, and reducing hysteresis and improve security. It also solves the problems in the self-energizing disc brake in Patent Application No. 201110291009.9, in which both sides of the brake disc need an inclined surface, resulting in the complicated structure, the low stiffness of the jaw, too many parts to be sealed, and the troubles of sealings.